At the core of the Learned Helplessness system is a dark isolation cube, in which the subject is placed, and a controller. The chamber is outfitted with an electrified grid floor, and connected to the controller which consists of a shock generator, as well as a timer that incorporates timing and randomizing. Shocks can be randomized on the basis of duration as well as by interval between shock events.
Also, more complex trains of shocks can be programmed. This system is expandable, for stimulation of up to 4 animals simultaneously. Mouse or Rat cages are available. When rodents are exposed to inescapable and unpredictable stress, such as forced swim or inescapable footshock, they often develop deficits in memory and learning tasks (e.g. Active Avoidance), and often show also analgesic reactions (S.I.A. Stress-Induced Analgesia).